Electromagnet.



No. 775,145. PATENTED Npv. 15,1904.

w. MEYER. ELEGTROMAGNET.

. APPLICATION FILED AUG. 26, 1901. NO'MODBL. I 2 SHEETS-SHEET l.

w Ivzverziar. a zfrzebus'es: wiZiz'w/rz i No. 775.145.- PATENTED NOV.15, 1904.

W. MEYER.

ELEGTROMAGNET.

APPLICATION FILED AUG. 26, 1901. .NO MODEL. 2 SHEETS-SHEET 2.

Ivzvenar: willz'am CIeyev;

UNITED STATES Patented November 15, 1904.

PATENT OFFICE.

WILLIAM MEYER, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE AS- SIGNMENTS,TO KELLOGG SWITCHBOARD & SUPPLY COMPANY, OF CHICAGO, ILLINOIS, ACORPORATION OF ILLINOIS.

ELECTROMAGNET- SPECIFICATION forming part of Letters Patent No. 775,145,dated November 15, 1904.

Application filed .Iugus; 26, 1901. Serial No. 73,357. (No model.)

To (1 whom it may concern:

Be it known that LWILLIAM MEYER, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a certain new and useful Improvement in Electromagnets, ofwhich the following is a full, clear, concise, and exact description,reference being had to the accompanying drawings,forming a part of thisspecification.

My invention relates to electromagnets, and has for its object theprovision of an improved construction thereof toprocure more efficientoperation, and to, simplify its mechanism.

My invention further relates to relays comprising the combination of myimproved electromagnet with circuit-changing switching mechanismcontrolled thereby.

My invention may generally be described as comprising an electromagnethaving a magnetic circuit that is practically closed, this magneticcircuit including a movable armature having an angular extension,preferably also composed of iron, to thereby constitute a bell-cranklever, which armature is arranged to engage the free end of acircuit-changing spring or springs near its pivotal mounting,

whereby a most compact and efficient structure is secured. The armatureof the electromagnet entering into the construction of the relay ispreferably free of any pivot or trunnion pins or screws, being mountedto have the corner formed by the sides thereof engaged by the cornerportion of a bar composed, preferably, of metal and preferablyconstituting part of the magnetic circuit. This armature in the form ofa bell-crank and the said bar are prevented from displacement by meansof a single screw passing through the armature into the bar. Theconstruction is thus very much simplified and the cost of the partsmaterially reduced. To secure the most effective operation, the arms orsides ofthe bell-crank lever are displaced slightly more than ninetydegrees, the displacement being suflicient to secure the requiredrotation of the armature.

I will explain my invention more fully by reference to the accompanyingdrawings, in which Figure l is an elevation of my improvedelectromagnetic mechanism; Fig. 2, a plan view of the structureillustrated in Fig. 1; Fig. 3, a longitudinal sectional elevation of thestructure; Fig. 4, a front view thereof. Fig. 5 illustrates theadaptation of the relay to a telephone-exchange system, the relayserving, as illustrated in this figure, as a cutoff relay.

Like parts are indicated by similar characters of reference throughoutthe dilferent figures.

I will first describe the telephone-exchange system in connection withwhich my improved instrument is employed and will thereafter moreparticularly set forth details of the instruments construction.

For the sake of clearness I have diagrammatically shown the cut-oifrelay in the drawings as provided with two armatures, one mounted ateither extremity thereof, while it is readily understood that in thepreferred embodiment of my invention I have but a singlespring-actuating armature.

' At the substations 90 and 120 are illustrated well-known types oftelephonic apparatus. At each station there is provided asignal-receiver 1, a telephone-transmitter 2, a primary winding 3, and aswitch-hook 4 for including the hell 1 in circuit when the receiver 5 isin place upon the hook and for excluding this bell from circuit andincluding instead thereof the transmitter 2 with the primary winding 3when the receiver is removed from its hook. There is also included in alocal circuit with the receiver 5 the secondary 6 of a transformer.Other types of telephone-station apparatus, however, may be employed.

Telephone-lines extend by their limbs? and 8 to the springs 9 and 10 ofthe cut-off relay 11 of my improved form. The limb 7 extends when thespring 9 is-in engagement with its normal contact through the winding ofthe relay 12 to one terminal of the common battery 13, in this instancethe positive terminal, the limbs 7 thus when idle having commonconnection with this terminal of the battery. The limb 8 by reason ofthe engagement of the spring 10 with its normal contact is normallyconnected with the remaining terminal of the battery. Thus the batteryis normally in bridge of the telephone-lines; but the condensers at thesubstations prevent the flow of this battery by way of thetelephone-lines when the telephone-receivers are upon theirswitclrhooks.

W'hen a subscriber initiates a call by removing his receiver from itstelephone switclr hook, the common battery 13 is closed through thewinding of the relay 12, which thereupon attracts its armature, therebyuniting the contacts 16 and 17 to actuate the correspondingline-indicator 18, that is thus included in a local circuit with acommon battery, and also closes the terminals 19 and 20 together.whereby one terminal of the common battery, in this instance thenegative terminal, is connected with the test-thimbles of thespringjacks 22, distributed over the various sections of the multipleswitchboard. Cord-circuits may be employed, one of which is illustrated.comprising in this instance answering and conl'iecting plugs 23 and 24,the tips whereof are united by a tip strand, while the sleeves areunited by a sleeve-strand that includes in circuit therewith theoperating-windings of the supervisory relays 25 and 26, a bridgeconductor 27 being included between these windings and including aresistance 28, whereby the control of these supervisory relays may beindependently effected by the corresponding subscribers apparatus, eachsupervisory-relay coil being provided with a sup plemental winding 29,these windings being included in a closed local circuit. .It is notdeemed that a further description of the cordcircuit is essential, assuch circuits generally are well known to those skilled in the art.

The operator in connecting subscribers for conversation closes circuitthrough the windings of the cut-off relays, the armatures thereofserving to move the springs 9 and 10 from their normal to theiralternate contacts, thereby removing the line-indicators.

Referring now more particularly to Figs. 1, 2, 3, and L, theelectromagnet of each relay has its armature in the form of a bell-crank30, pivoted at its elbow. For the purpose of a good magnetic circuit theentire bell-crank lever is preferably composed of soft iron, though thestructural advantages possessed by the electron'iagnet may be obtainedwithout constructing the bell-crank lever entirely of iron. Theari'nature portion of the bellcrank lever is directly opposed to thecore 31 of the electromagnet, which at its upper end is united to anangular bar 32, composed, preferably, of iron to secure a good magneticcircuit. This bar 32 projects over the top of the electronmgnet intoengagement with the horizontal extension of the armature, which rocksupon the bar. The upper or horizontal arm of the bell-crank lever isdisposed beneath the springs 9 and 10, the said arm havinginsulating-buttons 33, that engage the springs and serve upon theactuation of the armature to move the arms from the normal to thealternate contacts. In order to offectually insulate the front ends ofthese springs from each other and from the bar 32 and to hold them intheir proper relative positions, an insulating-pin is provided for eachset. This pin has an enlarged head 36 adapted to rest upon the metallicbar 4, while its shank 37 extends through an aperture in the lowerspring of the set, the said aperture being too small to permit saidenlarged head of the pin to pass therethrough. The central spring, suchas S) or 10, of the set is provided with an enlarged aperture throughwhich the shank 37 of the pin freely passes, while the outer or upperspring of the set is adapted to rest upon the ends of the said shank 37.The inner and outer springs being given a normal tension or trend towardthe support or bar 32, the insulating-pin holds them in proper normalposition, while the middle spring is permitted to freely vibratetherebetween. At the same time the pin itself is held in place upon thebar 32 by the inner spring of the set pressing against its enlargedhead. The springs 9 and 10 at the buttons are free and are anchored atthe other end of the electromagnet. I prefer to pivot the bell-crank leVer upon the engaging strip or bar by having one corner of the barengage the inner corner of the bell-crank lever, whose arms arepreferably displaced slightly more than ninety degrees to permit thebell-crank lever to rotate upon this corner throughout a sufficientrange to secure proper operation of the magnet. To prevent adisplacement of the bellcrank lever, 1 provide the same with an aperturethrough which a screw 34, secured to the bar 32, is passed, a split nutengaging the screw to prevent end wise displacement of the bell-cranklever.

\Vhere it is desired to secure a good magnetic circuit, the horizontalextension of the arm, or a portion thereof, should be made of iron toform with the bar 32 and the core of the magnet the magnetic circuit.

Having thus described my invention, 1 claim as new and desire to secureby Letters Patent 7 1. In an electromagnet, the combination with aUshaped frame, of magnetic material, one leg thereof forming the coreand provided with an energizing-coil, of an angular armature poised onthe end of the other leg and adapted by attraction by the core to closethe magnetic circuit through the core and said other leg, substantiallyas described.

2. In an eleetromagnet, the combination with a magnet-core, of a bar ofmagnetic material connected therewith at one end, and an angulararmature poised upon and in contact with the other end of the bar andadapted, upon being attracted by the core, to form a closed magneticcircuit with said core and said bar, substantially as described.

3. The combination with an electromagnet provided with a bar of magneticmaterial, of an armature for the magnet made in the form of a bell-cranklever poised upon and in contact with the end of said bar, said barbeing adapted by means of said armature to form a closed magneticcircuit with the magnet-core, substantially as described.

4. The combination with an electromagnet, of an angular-shaped bar ofmagnetic material, one of whose portions is arranged across the end ofthe electromagnet and connected with the core thereof, and the other ofwhose portions extends from end to end of the magnet along the sidethereof, and an armature made in the form of a bell-crank arranged atthe end of the magnet opposite that of the cross portion of the saidbar, the said armature being poised upon and in contact with theadjacent end of said bar,-one of its portions extending along the sameand the other extending downwardly into position opposite the end of themagnet-core, substantially as described.

5. In an electromagnet, the combination with a U-shaped frame ofmagnetic material having its legs disposed one above the other. thelower leg forming a core, of a helix wound upon said core, aninverted-L-shaped armature poised so that the inner face of the bendthereof engages the frontedge of the upper leg of said frame, saidarmature being adapted upon energization of said helix to be attractedtoward said core portion to form a closed magnetic circuit with the legsof said frame, substantially as described.

6. The combination with a magnet, of an armature therefor having twoarms at an angle to each other, a support for the armature having anedge upon which as a fulcrum said armature is carried intermediate ofits ends and may rock, said armature being adapted to be actuated bysaid magnet when the same is energized, and parts adapted to be actuatedby said armature, substantially as described.

7 The combination with a magnet, of an armature therefor comprising twoarms extending at an angle to each other, a member having a corner oredge fitting with the apex of said angle and forming a support for thearmature upon which as a fulcrum it may rock, said armature tending whenthe magnet is energized, to shorten the path for the magnetic lines offorce, and parts adapted to be actuated by said armature, substantiallyas described.

8. The combination with a magnet, of an armature therefor having twoarms extending at an angle to each other, a support having a knife-edgeto form a support for the armature intermediate of its ends and uponwhich as a fulcrum it may rock, one of said arms of the armature servingto complete the magnetic circuit of the magnet. and parts adapted to beoperated by said armature when it is ac-. tuated. I

9. The combination with a magnet having a core, of a member secured tothe rear end of the core and serving to extend the magnetic circuit ofthe magnet toward the forward end thereof, an armature having two armsat an angle to each other and supported upon a suitable edge upon whichas a fulcrum it may rock, said armature tending to bridge the gapbetween the fixed poles of the magnetic circuit when the magnet isenergized, and parts adapted to be actuated by said armature, sulstantially as described.

10. The combination with amagnet-coil,of a core therefor provided withmetallic parts forming an external magnetic circuit normally open at oneportion, a bent armature having two arms at an angle to each other sosupported as to close the normally open portion or gap in the externalmagnetic circuit or to shorten the path for the lines of force when thecore is magnetized, a support for said armature having an edge uponwhich it rocks as'a fulcrum and a bunched set of flat superposedswitch-springs carrying contacts adapted to be operated by one of saidarms of the armature when attracted, substantially as described.

11. The combination with a magnet-coil, of a core extending through thecoil, a part to which said core is secured at its rear end, said partextending parallel with the coil to a point adjacent to the forward endof the core, an armature for the magnet having two arms at substantiallyright angles to each other, said armature riding loosely upon theforward end of said part and upon which as afulcrum it is supported torock, one arm thereof standing in front of the magnet-core in positionto be attracted thereby, said armature having an aperture transverselytherethrough, a retaining device passing through said aperture and intosaid part to secure the armature in place, and a set of switch-contactsactuated by said second arm of the armature, substantially as described.

12. The combination with amagnet coil and core, of a support having anouter surface substantially parallel therewith and terminating at itsforward end substantially flush with the end of the core, an armaturehaving two arms extending at an angle slightly greater than a rightangle to each other and loosely carried upon said forward end as afulcrum with one arm extending in front of the coil and core' inposition to be attracted thereby and the other arm extending back uponsaid support, switch-springs actuated by said second arm and normallypressing it into engagement with the face of the support, whereby whenthe coil is energized the one arm of the armature is attracted and theother arm lifted to actuate the switch-springs, and when theenergizing-current 18 cut off the said springs restore the armature tonormal position.

13. The combination with a set of flat superposed switch-springs rigidlysecured together, of a supporting and spacing stud for the free ends ofsaid springs, said stud having an enlarged head between one of thesprings and an adjacent support, the said spring tending to hold thesaid stud in place and the said head serving to properly space thespring from the support, the shank of said stud passing through asuitable aperture in the adjacent spring, and a third spring restingupon the end of said shank and being held thereby at the desireddistance from said support and first spring, the aperture in theintermediate spring being large enough to permit it to be freelyvibrated, substantially as described.

14. The combination with a set of fiat superposed contact-springsrigidly secured together, of a support for said springs to which theyare firmly secured, an insulating supporting and spacing stud for thefree ends of said springs, said stud having an enlarged head between theinner spring and the support to hold said spring at the desired distancefrom the support and the spring tending to hold the stud in place, saidstud having a shank passing through the inner springs of the set, theouter spring resting upon the end of the shank and being spaced therebyat the desired distance from the adjacent spring, the aperture in theintermediate spring being large enough to permit it to freely vibratebetween the inner and outer springs, substantially as described.

15. The combination with a magnet-coiLof a member extendinglongitudinally thereof, an armature for the magnet having two armsextending at an angle to each other, one arm passing transversely acrossthe end of the magnet in front of its pole so as to be actuated therebywhile the other arm extends back over the said member, a set ofsuperposed switchsprings and alternately-disposed strips of insulation,screws passing through said springs and strips to clamp them togetherand to the said member, the free ends of said springs terminatingadjacent to the said second arm of the armature, and one of said springsextending beyond the others to the said second arm of the armature,whereby when the magnet is energized the said spring is lifted and whenthe magnet is deenergized the spring returns the armature to normalposition, substantially as described.

In witness whereof I hereunto subscribe my name this 1st day of August,A. D. 1901.

\VILLIAM MEYER.

Witnesses:

GEORGE L. URAGG, HERBERT F. OBERGFELL.

